In global system for mobile communications (GSM) networks, A5 ciphering is one technique used to protect data (e.g., such as user data and signaling information) at the physical layer. For example, the A5 ciphering algorithm is used to secure communications on the traffic channel (TCH) and on its associated control channels, such as the fast associated control channel (FACCH) and the slow associated control channel (SACCH). However, some information that is transmitted securely over the SACCH using A5 ciphering is also broadcast as plaintext (or, in other words, unciphered) on the broadcast channel (BCCH). An attacker could compare the plaintext information broadcast on the BCCH with ciphered information captured by monitoring a SACCH to recover the ciphering key employed by the A5 ciphering algorithm, thereby allowing the attacker to gain access to other information that has been A5 ciphered using this ciphering key.